ANCHORAGE, ALASKA -- It
was likely easier than ever to see a migrating trumpeter swan this year, as the
big white birds continued a remarkable comeback from near extinction in the
Lower 48 states and much of their Alaska habitat, a federal wildlife biologist
said.
"They still have not
recovered to their full range that they once occupied prior to the 1880s, but
they've done fantastically in Alaska," said Deborah Groves, who has
counted Alaska swans since 1990.
A 1968 Alaska census found just
2,847 of the birds. Random sampling in 2010 estimated 25,347 - a nearly
ninefold increase.
Trumpeters are known for their
distinctive call that the Cornell Lab of Ornithology calls "hollow, nasal
honking." The Alaska Department of Fish and Game says it's deep, like a
French horn.
With 7-foot wingspans,
trumpeters are North America's largest waterfowl. Males average 28 pounds,
females 22 pounds, and eggs are up to 5 inches long, the department says.
The birds were hunted
throughout the 1800s for meat and feathers, which made fine quill pens. By the
early 1930s, Groves said, there were only 69 known trumpeters in Yellowstone
National Park.
Hunting ended and biologists
made a happy discovery when they began bird work in Alaska: A remnant
population of a couple of thousand trumpeters remained, Groves said.
Alaska biologists did their
first formal trumpeter survey in 1968, another in 1975 and every five years
since then.
"They were increasing
almost exponentially for a while," Groves said.
Biologists in 2005 detected a
continued boom, even though they suspected the habitat of the birds was
saturated. By 2010, the count switched to sampling rather than a census because
of the trumpeters' wide range.
Read more here: http://www.kansascity.com/2012/10/30/3892457/alaska-trumpeter-swans-filling.html#storylink=cpy
No comments:
Post a Comment